There are opposing views on the extent to which interactivity is really going to become a part of our day-to-day TV viewing. Predictably there are equally committed zealots at either end of the conversational spectrum either dismissing the notion completely or declaring interactivity an inevitability waiting to happen.
The reality is of course, likely to be somewhere in the middle, with some programs and some advertising offering different types of interactivity that different audience segments will take advantage of on different occasions (the trick lies in defining where the money is in all this).
Experience from overseas (notably the UK) and some activity here in the US suggests that as far as interactive advertising is concerned, creatives are going to have a whole new dimension to deal with. Issues of effectiveness and accountability have always been the source of tension between the creative and client side of the advertising equation, but when a 30-second spot has to not only effectively communicate a message or call to action, but also facilitate some sort of direct on-screen interaction, the evil specter of usability raises its (to some) ugly head.
After all, if a viewer is sufficiently moved to interact with an ad (and, yes it does happen), then its kind of important that the interface design is conducive to making it happen.
This isnt only relevant to direct response ads either. Interactive ads (or iAds as they are often called) have demonstrated a real ability to impact against branding metrics too, as consumers become more immersed in an advertiser-supplied experience. Its at this point where the usability of the interface is a very real part of how the brand communicates itself.
In the future then, look for ad copy testing to evolve to include usability testing to determine how much and which parts of the screen are utilized for which purpose. Getting it right can lead to more time spent with the brand, enhanced consumer response and data captured through requests for information, competition entries etc. Getting it wrong could end up with otherwise perfectly good advertising leaving a bad taste in the consumers mouth